Institute of Chemistry
Changchun Institute of Applied Chemistry, Chinese Academy Of SciencesNot a member yet
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Growth mechanism and active site probing of Fe3C@N-doped carbon nanotubes/C catalysts: guidance for building highly efficient oxygen reduction electrocatalysts
No full textNon-platinum (NP) electrocatalysts with high activity and durability for oxygen reduction reactions (ORR) are required for fuel cells and other renewable systems. To avoid trial-and-error methods and achieve the rational design and synthesis of efficient NP catalysts, in-depth knowledge of the formation/growth mechanism of nanocatalysts and the origin of active sites is highly desirable. Here, we report a new class of NP catalysts with a novel structure of Fe3C encapsulated in N-doped carbon nanotubes/C. We study the formation mechanism of the nanostructure to pave the way for controlled fabrication of high-performance NP catalysts. The encapsulation of iron into carbon occurs during the first step of CNT growth and the surface functional groups on carbon black are identified as being essential for forming CNTs. The catalyst shows ultrahigh catalytic performance in both acid and alkaline media. We also examine the structure-performance dependency. The catalytic performance is highly dependent on the nanostructure and the encapsulation of Fe3C. Fe affects the catalytic performance through electronic effects rather than by directly participating in the active sites. This result is confirmed by DFT calculations, which show an increase in the density of states and a reduction in the local work function, XPS studies, and electrochemical measurements. The likelihood of N participating in the active sites is low because the catalytic performance does not depend on pyridinic and graphitic N
The important role of surface ligand on CdSe/CdS core/shell nanocrystals in affecting the efficiency of H-2 photogeneration from water
No full textThe use of colloidal semiconductor nanocrystals (NCs), especially those with a core/shell structure, for photocatalytic hydrogen (H-2) production from water is currently one of the hottest research fields. Although the ligand on the semiconductor NC surface is crucial to the optical and optoelectronic properties of the NC, the study of the ligand effect on the photocatalytic activity of H2 generation is rarely reported. Herein, we employ nearly monodispersed CdSe/CdS core/shell NCs as a model photocatalytic system, and three kinds of ligands with different numbers of functional thiol groups (i. e., poly(acrylic acid), 3-mercaptopropionic acid and 2,3-dimercaptosuccinic acid) are selected as the ligands to investigate the effect of ligand on the efficiency of H-2 photogeneration. The results show that the H-2 photogeneration efficiency is highly dependent on the surface ligand of the NCs, and it increases with the increase of the number of the functional thiol groups in the ligand, and correspondingly, the photoluminescence intensity and average fluorescence lifetime, which are measured by steady state and time-resolved fluorescence measurements, are decreased. The surface trap-related charge separation efficiency, which is mediated by surface coating with different ligands, is supposed to cause the distinct ligand-dependent performance in the H-2 evolution
Trimetallic PtCuCo hollow nanospheres with a dendritic shell for enhanced electrocatalytic activity toward ethylene glycol electrooxidation
No full textIn this work, by utilizing galvanic replacement reaction, a simple method for the synthesis of trimetallic PtCuCo hollow nanospheres with a dendritic shell is demonstrated. The compositions of the nanospheres can be well controlled, and the electrocatalytic activity can also be modulated by adjusting their compositions. Electrocatalytic results show that all of the as-prepared trimetallic PtCuCo nanomaterials show better catalytic performance toward ethylene glycol electrooxidation than the commercial catalyst
Synthesis and phase transition of wurtzite Cu3ZnInSnS6 nanodisks
No full textWurtzite Cu3ZnInSnS6 (CZITS) nanodisks were successfully synthesized according to rational design via a hot-injection method. Their suitable band gap and photoresponsive behavior indicate great potential application in solar cells. The structure of CZITS transforms to a tetragonal type after annealing, which is accompanied by grain growth
An anti-fouling aptasensor for detection of thrombin by dual polarization interferometry
No full textAn anti-fouling surface was designed to effectively resist nonspecific protein adsorption using dual polarization interferometry, based on which the aptasensor for detection of thrombin was fabricated according to the specific interaction between thrombin and its 15-mer aptamer
Detection of telomerase on upconversion nanoparticle modified cellulose paper
No full textHerein we report a convenient and sensitive method for the detection of telomerase activity based on upconversion nanoparticle (UCNP) modified cellulose paper. Compared with many solution-phase systems, this paper chip is more stable and easily stores the test results. What's more, the low background fluorescence of the UCNPs increases the sensitivity of this method, and the low telomerase levels in different cell lines can clearly be discriminated by the naked eye
Nanofibrous microspheres via emulsion gelation and carbonization
No full textNanofibrous hydrogel microspheres are formed by pH gelation of perylene diimide derivatives in emulsion droplets. These microspheres are freeze-dried and subsequently carbonized to produce discrete N-doped nanofibrous carbon microspheres. The carbon microspheres show high performance as electrode materials for supercapacitors
一种PVC搪塑工艺用环保高效液态复合热稳定剂及制备方法
No full text本发明涉及一种PVC搪塑工艺用环保高效液态复合热稳定剂及制备方法,具体涉及一种适用于汽车仪表板的软质PVC表皮搪塑成型的液态复合热稳定剂,该稳定剂通过复配多元醇类辅助热稳定剂而显著提高PVC粉料搪塑加工中的热稳定性尤其是中后期热稳定性,并通过用高分子量的极性酯类增塑剂取代传统的液态钙锌复合热稳定剂中的有机小分子溶剂而显著降低PVC搪塑表皮的热挥发损失
聚对苯二甲酸乙二醇酯复合材料及其制备方法
No full text本发明公开了一种聚对苯二甲酸乙二醇酯复合材料及其制备方法,属于复合材料技术领域。解决了现有技术中聚对苯二甲酸乙二醇酯结晶速率低,使用成核剂改性后分子量降低,力学性能劣化的技术问题。本发明的聚对苯二甲酸乙二醇酯复合材料包括100重量份的烘干的聚对苯二甲酸乙二醇酯和1～5重量份的烘干的多面体低聚硅倍半氧烷,其中,多面体低聚硅倍半氧烷含有羧基、环氧基中的一种或两种,且羧基和环氧基的总数在两个以上。该复合材料的结晶度能够达到30.2～33.9％,半晶周期能够达到1.1～2.1s,拉伸强度为62～76MPa,缺口冲击强度为2.8～4.5kJ/m2,热变形温度为79～92℃
一种β-内酰胺化合物的制备方法
No full text本发明一种β-内酰胺化合物的制备方法,属于药物化学领域。该方法以阿莫西林三水合物和6-氨基青霉素烷酸为原料,成功合成了β-内酰胺化合物(2S,5R,6R)-6-((2S,5R,6R)-6-((R)-2-氨基-2-(4-羟基苯基)乙酰氨基)-3,3-二甲基-7-氧代-4硫杂-1-氮杂双环[3.2.0]庚烷-2-甲酰胺)-3,3-二甲基-7-氧代-4-硫杂-1-氮杂双环[3.2.0]庚烷-2-甲酸,该制备方法条件温和,制备方法简单,能实现大批量合成